DESCRIPTION: (Applicant's abstract) L-glutamate is one of the key neurotransmitters and plays a primary role in synaptic plasticity. Long-term changes in synaptic efficacy of excitatory synaptic neurotransmission are considered to be the basis for learning and memory. Existing methods to measure L-glutamate concentration involve microdialysis, followed by detection using enzyme-based microelectrodes, high-performance chromatography, or capillary electrophoresis. These methods suffer from a) difficulties in quantitation, b) poor temporal resolution (>2 minutes), and c) interference from L-ascorbate; they have been used due to lack of better sensing mechanisms. Intelligent Optical Systems, Inc. (IOS) proposes to develop a real-time fluorescent optrode sensor for in vivo monitoring of L-glutamate concentration in rat brain cells. The proposed device will eliminate several bottlenecks affecting existing methodologies, and will substantially advance brain research. To achieve this goal we will develop fluorescent probes for L-glutamate based on photoinduced electron transfer. These fluorescent probes will be immobilized on multiple micron-sized fiber optic probes. Detection and imaging systems will be developed to monitor the dynamic and spatial changes occurring in L-glutamate concentrations in rat brain cells. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE